PHILOSOPHICAL SOCIETY OF WASHINGTON. 133 



Survey at the mouth of the ravine, on the southeastern shore of the 

 Big Diomede Island, in Behring Strait, is, therefore, in 



Latitude, 65 44/ 51" N. 



Longitude, 169 04 25 ± 10 V W. Gr. 



From bearings and angles taken from the astronomical station 

 and from the schooner at anchor, using the distance of the schooner 

 from the station as a base line, together with other bearings taken 

 while in the vicinity of the islands, a sketch of the two islands has 

 been prepared from which it appears that the meridian tangent to 

 the extreme eastern edge of the larger island is 2.1 nautical miles, 

 and the meridian tangent to the extreme western edge of the smaller 

 island is 3.1 nautical miles, east of the astronomical station. The 

 boundary line is to pass midway between these meridians, i. e. the 

 meridian which forms the boundary is 2.6 nautical miles east of the 

 astronomical station. 



In latitude 65° 45', the latitude of the astronomical station, 2.6 

 nautical miles is equal to 6' 20" of longitude, and, deducting this 

 from the longitude of the astronomical station, the longitude of the 

 boundary line is found to be 



168 58' 05" W. Gr. 



If we assume an uncertainty of one quarter of a nautical mile, 

 equal in this latitude to 37" of longitude, in thus transferring the 

 position of the station to the boundary line, and this seems to be 

 quite large enough, we have finally as the longitude of the boun- 

 dary line between Alaska and Eastern Siberia 



o / // // 



168 58 05 ± 38 



or, in time, 



h. m. s. s. 



II 15 52.3 ± 2.5 W. Gr. 



Errata. 



Page 126, line 6 from bottom, for " and returning " read " and after returning." 

 For " Behring," read " Bering," throughout this article. 



